Eventloop

[tramchamploo]

1. Invent an eventloop to schedule queue flush, so thread count is not reporter-bounded.
2. Each queue are bounded to specific eventloop, so there will be only one consumer.
3. A MPSC queue is used to schedule tasks. The messages will also be offered in this sort of queue.
4. So the message queue will be non-blocking, which means the block overflow-strategy will no longer exist.
5. So if a message is rejected, users want it blocked should implement their own RejectedHandler

• [x] An eventloop that execute tasks or schedule them at a fixed rate.
• [ ] A selector that select the ready(full) queue.
• [x] Use jctools MPSC queue as the message queue.
• [ ] Adjust overflow strategy to make compatible with the message queue.
• [ ] AsyncReporter binds a queue to an eventloop when created.
• [ ] Schedule a flush task of a message queue at a fixed rate to the eventloop.